The present invention relates to a side airbag apparatus that deploys and inflates an airbag at a side of an occupant seated in a seat of a vehicle when an impact is applied to the vehicle from a side of the vehicle seat, and protects the occupant from the impact by the airbag.
A side airbag apparatus that includes an airbag and an inflator has been widely known. In a case where an impact is applied to a motor vehicle from a side of a vehicle seat on which an occupant is seated due to a side collision and the like, such a side airbag apparatus protects the occupant from the impact. The airbag includes an inflation portion that inflates by inflation gas generated by the inflator. The airbag including the inflation portion is installed in a side part of a seat back of the motor vehicle seat together with the inflator in a folded state.
In the above described side airbag apparatus, when an impact is applied from a side to a motor vehicle configuring member (body side portion) configuring the side part of the motor vehicle, for example a side door, the inflation gas from the inflator is supplied to the inflation portion of the airbag. The airbag is inflated and deployed by the inflation gas, breaking the side part of the seat back, and is projected out from the motor vehicle seat in a state in which a part of the airbag is left within the seat back. The airbag enters a space between the motor vehicle seat and the body side portion, and is inflated and deployed frontward. The airbag is located between the occupant and the body side portion entering toward a motor vehicle interior side to restrain the occupant, and also to protect the occupant by reducing the impact from the side transmitted to the occupant through the body side portion.
An example of the side airbag apparatus is configured such that an inflation portion is divided into an upstream inflation portion, to which inflation gas from an inflator is supplied, and a downstream inflation portion adjacent to the upstream inflation portion by a dividing portion, and that the dividing portion is provided with an opening and a pressure regulator valve (for example, see JP 2012-30614 A).
The pressure regulator valve closes before an occupant restraint by the upstream inflation portion, so as to restrict the inflation gas from flowing to the downstream inflation portion from the upstream inflation portion through the opening. Therefore, internal pressure of the upstream inflation portion within the inflation portion mainly increases, and the upstream inflation portion is inflated and deployed. Further, upon the occupant restraint by the upstream inflation portion, the pressure regulator valve opens by an external force applied due to the restraint. By this opening incident, the inflation gas in the upstream inflation portion flows out to the downstream inflation portion through the opening. By this flow-out incident, the internal pressure of the upstream inflation portion decreases and internal pressure of the downstream inflation portion increases, whereby the downstream inflation portion is deployed and inflated.
By the aforementioned operation of the pressure regulator valve, a property of load that the occupant receives through the airbag can be made to be suitable for appropriately restraining and protecting the occupant, such that it reaches a predetermined value within a short period of time and thereafter maintained at the predetermined value.
However, in the aforementioned side airbag apparatus, although the pressure regulator valve can be opened and closed according to a restraining circumstance of the occupant by the upstream inflation portion and cause the inflation gas in the upstream inflation portion to flow out from the opening, the flow-out thereof is performed uniformly. If the flow-out of the inflation gas from the opening can be performed in various manners, it is expected that the performance of restraining and protecting the occupant by the airbag is improved.
This applies similarly to a side airbag apparatus in which only the opening among the opening and pressure regulator valve is provided at the dividing portion. Further, the above matter applies similarly to a side airbag apparatus in which the inflation portion is not divided by the dividing portion and the opening and pressure regulator valve are provided in a wall portion of the inflation portion, and it applies to a side airbag apparatus in which the inflation portion is not divided by the dividing portion and only the opening among the opening and pressure regulator valve is provided on the wall portion of the inflation portion.